Bales or batches of wet chip materials often are generated in the course of machining operations. The wet chip materials include both relatively small wet chips, referred to herein as granular wet chips, and stringy pieces of wet chips. The chips are covered or coated with lubricating, cooling or other fluid. Additionally, undesired solids such as bolts, nuts, etc. sometimes are found in the bales or batches of wet chip material.
Prior to sending wet chips to a centrifugal separator, where wet chips are separated into dry chips and fluids, such as is illustrated in Nemedi U.S. Pat. No. 5,106,487, the stringy wet chips generally must be shredded into granular wet chips. Otherwise, commercially-available wet chip separation systems sometimes will not function due to the large size of the stringy wet chips. The wet chip material is fed into a shredder apparatus where the stringy wet chips are shredded into granular wet chips that can be more readily transported in the wet chip separation system free from interfering with the wet chip separation process or damaging the wet chip separation equipment.
Shredder apparatuses for shredding wet chip materials are well known in the art. Often the shredder apparatus utilizes two rotatable shredder shafts each mounted in bearing units disposed in a shredder frame. Shredder members are disposed on each shaft, the rotating shredder members on one shaft cooperating with shredder members on the other shaft to shred wet chip material. Shredder apparatuses that employ a plurality of rotating shafts generally are relatively large, bulky units that, because of their size, are not adaptable to certain applications that have reduced space constraints.
In other applications, it is known to employ a wet chip shredder apparatus that utilizes a plurality of first shredder members disposed on a single rotatable shaft. A plurality of second shredder members is fixed to the shredder frame. In a shredding operation the first shredder members engage the second shredder members to shred wet chip material. An example of this type shredder is shown and disclosed in the co-pending application Ser. No. 10/100,786, filed by the present inventor on Mar. 19, 2002. While this shredder device is satisfactory for shredding wet chip material, it has been observed that lubricating and flume fluid can migrate to the location of bearing units that house the rotatable shaft. A concern exists that, over time, the fluid could possibly contaminate or otherwise damage one or more of the bearing units.
Further, it has been found in some applications that relatively heavy objects such as metal bolts, nuts, etc. are located in the bales of wet chip material. In some instances, these heavy objects can cause the shredder to jam. On such occasions, the shredder device must be stopped until the jam is cleared. In other situations, these heavy objects pass through the shredder and travel in the system with the potential for causing damage to a centrifugal wet chip separator or other parts of the wet chip separation system.